Freeze & Preserve Fresh Herbs in Olive Oil

Do you use your freezer to preserve herbs, vegetables, or fruit? The freezer can be a powerful, overlooked method of preserving. Pesto, strawberry puree, tomato soup — stash them away now for colder times! One of my favorite ingredients, a handful of fresh herbs from the garden, is one of the simplest things to preserve in the freezer, and I just learned a new, better way to freeze herbs: In oil!

I noticed a post at The Gardener's Eden (read it here) recommending that you freeze some herbs in oil. Why? Preserving herbs in oil reduces some of the browning and freezer burn that herbs can get in the freezer.

It's also a great way to have herbs ready immediately for winter stews, roasts, soups, and potato dishes. These dishes usually call for oil to start with, and so you can take a cube of frozen oil, herbs inside, out of the freezer and use this as the base of your dish. Cook the onions and garlic in this herb-infused oil and let the taste of herbs spread through your whole dish.

Given this use, the oil-and-freezer method of preservation works best with the tougher hard herbs such as rosemary, sage, thyme, and oregano. These are all herbs that would probably be cooked when added to a dish.

Soft herbs such as mint, basil, lemon verbena, and dill are usually added raw to a dish, and they don't respond as well to this kind of preserving. Their fresh taste is changed in the freezer, and honestly, I don't usually choose to freeze these delicate sorts of herbs at all, with the exception of homemade basil pesto. (Although I have been meaning to try this parsley freezing method from master gardener Margaret Roach!) Some folks do freeze soft herbs in bags without any water or oil, which essentially preserves them by drying them out. I don't prefer the taste of dried mint and other herbs, so I just never do this.

For me, the best use of the freezer when it comes to herbs is preserving hard herbs in oil or broth, although now I prefer oil. The aroma of the herbs really infuses the oil in the freezer, which is a bonus!

Here are some tips on preserving herbs in oil.

8 Steps for Freezing Herbs in Oil

Choose firm, fresh herbs, ideally from the market or your own garden.

If you wish, you can chop them fine. Or leave them in larger sprigs and leaves. Here I froze a combination of finely-chopped and whole herbs such as rosemary, fennel stalk, sage, and oregano.

Pack the wells of ice cube trays about 2/3 full of herbs.

You can mix up the herbs, too; think about freezing a bouquet garni of sage, thyme, and rosemary to add to winter roast chickens and potatoes!